Phase shifting device with rotatable cylindrical case having driver means on the end walls

ABSTRACT

Input is applied to a two-partition circuit that substantially equally distributes input power into two partitions having a phase difference of 90°, and the thus-distributed output is applied to a first driver that generates circularly polarized wave. The two outputs of the second driver, in which the circularly polarized waves generated from the first driver are coupled, are combined in a combining circuit. The end portion of the opening of the sealed case incorporating the first driver fits together with the end portion of the opening of the sealed case incorporating the second driver such that the two sealed cases together with the first and second drivers may rotate relative to each other around their cylindrical axis. The phase difference between the input of the two-partition circuit and the output of the combining circuit changes according to the relative angle of rotation around the cylindrical axis between first and second drivers.

This application is a continuation-in-part of application Ser. No.08/591,674, filed Jan. 30, 1996, now abandoned.

TECHNICAL FIELD

The present invention relates to a phase shifting device used in, forexample, a transmitting device capable of high output through paralleloperation of a plurality of transmitters and a power supply apparatusfor directional control of antennas.

BACKGROUND ART

When attempting to vary the direction of maximum radiation or side lobecharacteristic of an array antenna by appropriately controlling thedriving phase of each of a plurality of radiating elements forming thearray antenna, or when attempting to realize a high-output transmittingdevice by parallel-operating a plurality of transmitters and controllingthe output phase of each transmitter such that each is the same phase,line stretchers constructed so as to mechanically vary the length of thetransmission line of a signal, or waveguide-type phase shifting devicesformed by inserting a dielectric plate within a waveguide haveconventionally been used.

FIG. 1 presents several views of a waveguide-type phase shifting deviceof the prior art, FIG. 1A showing a plan view, FIG. 1B showing a sideview, FIG. 1C showing a sectional view taken at the B--B line of Fig.1B, and Fig. 1D showing a sectional view taken at the A--A line of FIG.1A.

In rectangular waveguide 11, flanges 12₁ and 12₂ are provided forinserting and connecting such a waveguide-type phase shifting devicewithin a rectangular waveguide circuit. A dielectric plate 13 isprovided within rectangular waveguide 11 such that the plate surface isparallel to the electric field within the waveguide 11. As shown in FIG.1D, the contour of this dielectric plate 13 is formed as aparallelogram, this parallelogram having inclines on the edges of theradio-wave incident side and edges of the opposite side which are formedso as to improve the radio-wave reflection characteristic at these edgeportions.

Instead of providing inclines to the edges of the radio-wave incidentside and edges of the opposite side of this dielectric 13, theradio-wave incident portion and opposite side portion of the dielectric13 may be formed such that the plate thickness gradually varies.

Support fittings 14₁ and 14₂ for dielectric plate 13 pass through theopposing short sides of rectangular waveguide 11 and dielectric plate13. Support fittings 14₁ and 14₂ may freely slide at the portions wherethey pass through the opposing short sides of rectangular waveguide 11but are secured to the portions where they pass through dielectric plate13.

Coupling plate 15 links together support fittings 14₁ and 14₂. Thiscoupling plate 15 serves as a handle for moving support fittings 14₁ and14₂ either forward or backward in the axial direction of each of supportfittings 14₁ and 14₂ while maintaining dielectric plate 13 in theattitude shown in Fig. 1D, thus allowing the plate surfaces ofdielectric plate 13 to be moved from a position coinciding with thecentral axis in the longitudinal direction of rectangular waveguide 11to a position close to either of the opposing short sides as shown inFIG. 1C, thus enabling variation in the proportion of shift change ofradio waves propagated through rectangular waveguide 11.

In other words, such a phase shifting device uses the change inpropagation speed of radio waves within rectangular waveguide 11according to the dielectric constant, thickness, and length in thedirection of wave propagation of dielectric plate 13. When interposed ata position coinciding with the central axis in the longitudinaldirection of rectangular waveguide 11, where the electric fieldintensity is at maximum strength, dielectric plate 13 exercises a largeeffect upon the propagation speed of radio waves, but the electric fieldstrength progressively weakens with distance from the longitudinalcentral axis of the rectangular waveguide 11 and proximity to either ofthe short sides, and consequently, as the position of insertion ofdielectric plate 13 shifts away from the central axis of rectangularwaveguide 11 and approaches either of the short sides, the effect uponthe propagation speed of radio waves decreases. Accordingly, the degreeof phase shifting can be varied by changing the position of insertion ofdielectric plate 13.

Support fittings 14₁ and 14₂ are maintained parallel to each other,their relative spacing (spacing in relation to the longitudinaldirection of rectangular waveguide 11) being selected as λ_(g) /4 (λ_(g)is the wavelength within the waveguide corresponding to the employedfrequency), whereby reflected waves arising at the support fitting 14₁closer to the radio-wave-incident portion and reflected waves arising atsupport fitting 14₂ which travel back to the position of support fitting14₁ are of mutually reversed phase and cancel each other, therebyenabling an improved reflection characteristic.

A line stretcher used in the prior art must regulate the line lengthaccording to the required degree of phase shifting, and therefore, whenthe required degree of phase shifting is great, not only is alarge-scale mechanical structure required, but a relativelytime-consuming and labor-intensive adjustment is required to accuratelymatch the line length with the degree of phase shift.

The waveguide-type phase shifting device shown in FIG. 1 involves thedrawbacks that a long dielectric plate 13 is required when a largeamount of phase shift is called for, resulting in a phase shiftingdevice of large overall size, and that a great deal of time and effortis required to adjust the insertion point of the dielectric plate 13 toaccurately match the amount of phase shift with the required value.

FIG. 2 shows a power supply circuit configured using phase shiftingdevices of the prior art for controlling the driving phase of subarrayantennas and for varying the direction of maximum radiation as well asthe side lobe characteristic of an array antenna. This power supplycircuit is configured from subarray antennas 16₁ -16₄ each composed of aplurality of element antennas, phase shifting devices 17₁ -17₃ of theabove-described prior art, transmission lines 18₁ -18₃ having a degreeof phase shift that serves as a standard, and two-branch circuits 19₁-19₃.

A phase shifting device of the prior art not only entails the samedrawbacks as the above-described line stretcher, but when used as shownin FIG. 2, in which a power supply circuit is configured for varying thedirection of maximum radiation or side lobe characteristic of an arrayantenna, further entails the drawback of complex structure of the powersupply circuit due to the need for transmission lines 18₁ -18₃ having anamount of phase shift that serves as a standard and two-branch circuits19₁ -19₃ for phase shifting devices 17₁ -17₃, respectively.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide a phase shiftingdevice which has a simple and compact structure, and which allows easyadjustment at the time of manufacture and easy handling during use.

To achieve the above-described objects, the present invention proposes aphase shifting device that includes:

two-partition circuit for partitioning input power into twosubstantially equal portions having a mutual phase difference ofsubstantially 90°;

a first driver for generating circularly polarized waves that is drivenby the two-partitioned output of the two-partition circuit;

a second driver for coupling circularly polarized waves generated by thefirst driver;

two sealed cases within which the first and second drivers are installedso as to be rotatable relative to each other around the axis joining thecenters of both drivers; and

a combining circuit for combining the two outputs generated fromcircularly polarized waves coupled in the second driver.

The two-partition output of the two-partition circuit, which distributesthe input power in two portions having a mutual phase difference ofsubstantially 90°, is applied to the first driver, which generates fromits front surface a circularly polarized wave. This circularly polarizedwave couples at the second driver, and the two outputs of the seconddriver arising from this coupled circularly polarized wave are combinedat the combining circuit. When the first and second drivers are rotatedrelative to each other around the axis that joins the centers of each ofthe first and second drivers, the phase difference between the input ofthe two-partition circuit that applies driver power to the first driverand the combined output of the second driver varies in accordance withthis rotation.

This phase shifting device allows variation of the degree of phase shiftover a range of from 0° to 360°, and moreover, has a simple and compactstructure that enables extremely easy adjustment at the time ofmanufacture and service during use. In addition, the relation betweenrelative angle of rotation of the two sealed cases and the degree ofphase shift is proportional, and therefore, the degree of phase shiftcan be read directly if graduations of degrees are added around thecircumference of one of the sealed cases and a pointer is added at apoint on the circumference of the other sealed case.

Furthermore, the present invention provides a phase shifting device thatincludes:

a first driver for generating linearly polarized waves that is driven byinput applied by way of an input terminal;

a second driver for coupling two orthogonal components of linearlypolarized waves generated by the first driver;

two sealed cases within which the first and second drivers are installedso as to be rotatable relative to each other around the axis joining thecenters of both drivers; and

a combining circuit for combining the two outputs generated by the twoorthogonal components of the linearly polarized wave coupled in thesecond driver.

When the first driver is driven, linearly polarized waves are generatedfrom the front surface of the driver, and the two orthogonal componentsof this linearly polarized wave are coupled at the second driver. Whenthe first and second drivers are rotated relative to each other aroundthe axis joining the centers of each of the first and second drivers,the phase difference between the input applied to the first driver andeither of the two outputs of the combining circuit to which the twooutputs of the second driver are applied varies according to the angleof rotation; and in addition, the phase difference between the twooutputs of the combining circuit to which the two outputs of the seconddriver are applied also varies according to the relative angle ofrotation between the first and second drivers.

This phase shifting device allows variation of the degree of phase shiftover a range of from 0° to 360°, and moreover, has a simple and compactstructure and enables extremely easy adjustment at the time ofmanufacture and handling during use. In addition, the relation betweenrelative angle of rotation of the two sealed cases and the degree ofphase shift is proportional, and therefore, the degree of phase shiftcan be read directly if graduations of degrees are added around thecircumference of one of the sealed cases and a pointer is added at apoint on the circumference of the other sealed case.

This phase shifting device is well-suited for control of the directionof maximum radiation or side lobe characteristics of an array antennabecause it both allows variation of the phase difference between theinput and either one of the two outputs of the combining circuitaccording to the relative angle of rotation between the sealed cases,and moreover, allows variation of the phase difference between the twooutputs according to the relative angle of rotation between the sealedcases.

BRIEF DESCRIPTION OF THE DRAWING

FIGS. 1A, 1B, 1C and 1D show an example of a waveguide-type phaseshifting device of the prior art;

FIG. 2 shows an example of the use of the prior-art phase shiftingdevice shown in FIG. 1;

FIG. 3 is a side view of a phase shifting device according to anembodiment of the present invention;

FIG. 4 is a side view of a coupler 21 shown in FIG. 3;

FIG. 5 is a plan view of coupler shown in FIG. 3;

FIG. 6 is a sectional view taken at line C--C of FIG. 4;

FIG. 7 is a sectional view taken at line D--D of FIG. 5;

FIG. 8 illustrates the operation of the phase shifting device accordingto the embodiment of FIG. 3;

FIG. 9 shows the return loss characteristic in coaxial connection plug21₃₁ of the phase shifting device of the embodiment shown in FIG. 3;

FIG. 10 shows the transmission loss characteristic between coaxialconnection plugs 21₃₁ and 21₃₄ of the phase shifting device of theembodiment shown in FIG. 3;

FIG. 11 shows the degree of phase shift in relation to the relativeangle of rotation φ between sealed cases 21₁ and 21₂ in the phaseshifting device of the embodiment shown in FIG. 3;

FIG. 12 shows the transmission loss characteristic between inputterminal 22₁ and output terminal 24₁ in the phase shifting device of theembodiment shown in FIG. 3;

FIG. 13 is a sectional view showing the principal parts of a phaseshifting device according to another embodiment of the presentinvention;

FIG. 14 is a sectional view showing the principal parts of a phaseshifting device according to another embodiment of the presentinvention;

FIG. 15 is a block diagram showing a phase shifting device according tothe embodiment of FIG. 13;

FIG. 16 is a side view of a phase shifting device according to anotherembodiment of the present invention;

FIG. 17 is a side view of coupler 31 within FIG. 16;

FIG. 18 is a plan view of coupler 31 within FIG. 16;

FIG. 19 is a sectional view taken at line G--G of FIG. 17;

FIG. 20 is a sectional view taken at line H--H of FIG. 17;

FIG. 21 is a sectional view taken at line I--I of FIG. 18;

FIGS. 22A and 22B show the electric field level produced by driveelement 31 and the outputs E₁ and E₂ of 90° 3-dB hybrid circuit 32 inthe phase shifting device of FIG. 16;

FIG. 23 shows the reflection characteristic in coaxial connection plug31₃₁ of the phase shifting device of FIG. 16;

FIG. 24 shows the transmission loss characteristic between coaxialconnection plugs 31₃₁ and 31₃₃ of the phase shifting device of FIG. 16;

FIG. 25 shows the degree of phase shift in relation to the relativeangle of rotation φ between sealed cases 31₁ and 31₂ in the phaseshifting device of FIG. 16;

FIG. 26 shows the observation results of the transmission loss betweencoaxial connection plug 31₃₁ of coupler 31 and the output terminal 32₃of 90° 3-dB hybrid circuit 32, and between coaxial connection plug 31₃₁of coupler 31 and output terminal 32₄ of 90° 3-dB hybrid circuit 32;

FIG. 27 shows an example of the use of both outputs E₂ and E₁ of outputterminals 32₃ and 32₄ of 90° 3-dB hybrid circuit 32; and

FIG. 28 is a sectional view showing the principal parts of the phaseshifting device according to another embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFFERED EMBODIMENTS

FIG. 3 is a side view of the phase shifting device according to anembodiment of the present invention.

The phase shifting device according to this embodiment is constructedfrom coupler 21 which includes cylindrical sealed cases 21₁ and 21₂which are each closed at one end, and terminals 21₃₁ -21₃₄ made up ofcoaxial connection plugs; 90° 3-dB hybrid circuit 22 which is composedof a directional coupler including input terminal 22₁, isolationterminal 22₂, and output terminals 22₃ and 22₄ ; reflectionlessterminator 23 connected to isolation terminal 22₂ ; 90° 3-dB hybridcircuit 24 which is composed of a directional coupler including outputterminal 24₁, isolation terminal 24₂, and input terminals 24₃ and 24₄ ;reflectionless terminator 25 connected to isolation terminal 24₂ ;coaxial cable 26₁ connecting output terminal 22₄ and terminal 21₃₁ ;coaxial cable 26₂ connecting output terminal 22₃ and terminal 21₃₂ ;coaxial cable 27₁ connecting terminal 21₃₄ and input terminal 24₃ ; andcoaxial cable 27₂ connecting terminal 21₃₃ and input terminal 24₄.

Here, the inside diameters of the cylindrical sealed cases 21₁ and 21₂are selected so as to give cutoff modes at the designed frequency forsmallness of the device. The output power of each of output terminals22₃ and 22₄ is 1/2 of the input power to input terminal 22₁, and, forexample, the phase of the output of output terminal 22₃ is substantially90° delayed with respect to the phase of the output of output terminal22₄. Furthermore, inputs of equivalent magnitude are applied to each ofinput terminals 24₃ and 24₄, the input to input terminal 24₃ being, forexample, substantially 90° advanced with respect to the phase of inputto input terminal 24₄.

The lengths of each of coaxial cables 26₁ and 26₂ are adjusted such thatthe phase of the output of output terminal 22₃ of 90° 3-dB hybridcircuit 22 is delayed substantially 90° with respect to the phase of theoutput of output terminal 22₄, and moreover, such that both outputs areapplied to input coaxial connection plugs 21₃₁ and 21₃₂ of coupler 21while being kept in a mutually equivalent relation. The lengths ofcoaxial cables 27₁ and 27₂ are each adjusted such that the outputs fromoutput coaxial connection plugs 21₃₃ and 21₃₄ of coupler 21 are appliedto the input terminals 24₃ and 24₄ of 90° 3-dB hybrid circuit 24 withthe phase difference and the equal amplitude relation between theoutputs maintained unchanged.

FIG. 4 shows a side view of coupler 21 of FIG. 3, FIG. 5 shows a planview of the sealed case 21₁ side of coupler 21 as seen from the bottomside, FIG. 6 is an enlarged sectional view taken along line C--C of FIG.4, and FIG. 7 is an enlarged sectional view taken along line D--D ofFIG. 5.

As can be clearly seen from FIG. 7, stepped portions are formed in theside walls at the end portions of the openings of both of sealed cases21₁ and 21₂, the end portion of the opening of sealed case 21₂ fittinginside the end portion of the opening of sealed case 21₁, the two sealedcases 21₁ and 21₂ being coupled together as a unit, and sealed cases 21₁and 21₂ being constructed so as to allow rotation relative to each otheraround their cylindrical axis.

Sealed cases 21₁ and 21₂ are manufactured by first machining a metalblock or press-forming a metal sheet in the prescribed shape; by forminga suitable synthetic resin in a preliminary form of the prescribed shapeand subsequently applying a metal film to the surface by a electrolessplating or vacuum evaporation process; or by multilayer stacking ofdielectric plates having an appropriate dielectric constant and formingas a cylinder with one closed end that shields electromagnetic energy inaccordance with Snell's law.

Coaxial connection plugs 21₃₁ and 21₃₂ each include internal conductors21₄₁ and 21₄₂. A round insulation plate 21₅₁ composed of a materialhaving excellent high-frequency characteristics and a thickness lessthan the transmission wavelength such as an organic material such aspolyethylene or fluorinated ethylene or an inorganic material such as aceramic is adhered to the inner surface of the bottom wall of sealedcase 21₁ using a suitable adhesive. Metal plate 21₆₁ is secured to thesurface of round insulation plate 21₅₁ using a suitable adhesive, and inaddition, portions of the periphery of metal plate 21₆₁ are connected tointernal conductors 21₄₁ and 21₄₂ of coaxial connection plugs 21₃₁ and21₃₂, and the first driver composed of a microstrip antenna is formedwith sealed case 21₁ on the opposite side of round insulation plate 21₅₁as the ground conductor, metal plate 21₆₁ as the first driver element,and the contact points between metal plate 21₆₁ and interior conductors21₄₁ and 21₄₂ of coaxial connection plugs 21₃₁ and 21₃₂ as the driverpoints.

As can be seen from FIG. 6, a right angle is formed by the straight linejoining the center of metal plate 21₆₁ and the driving point constitutedby the contact point between metal plate 21₆₁ and the interior conductor21₄₁ of coaxial connection plug 21₃₁ and the straight line joining thecenter of metal plate 21₆₁ and the driving point constituted by thecontact point between metal plate 21₆₁ and the internal conductor 21₄₂of coaxial connection plug 21₃₂.

In addition, the exterior conductors of each of coaxial connection plugs21₃₁ and 21₃₂ are electrically connected to sealed case 21₁ and as shownin FIG. 7, a portion of sealed case 21₁ has been removed around theperiphery of internal conductor 21₄₁ to form a gap such that internalconductor 21₄₁ makes no mechanical contact with sealed case 21₁, and agap is similarly formed in sealed case 21₁ at the portion around theperiphery of internal conductor 21₄₂.

As the method for securing metal plate 21₆₁ to the surface of roundinsulation plate 21₅₁, a setscrew in the center of metal plate 21₆₁ (theportion wherein electric field intensity is 0) may also be used tosecure the plate to round insulation plate 21₅₁ rather than an adhesive,or metal plate 21₆₁ may be screwed at its center to the bottom wall ofsealed case 21₁ through round insulation plate 21₅₁,

Instead of using metal plate 21₆₁, the driver element of the microstripantenna making up the first driver may be formed by applying a metalfilm to the surface of round insulation plate 21₅₁ by a process such asvacuum evaporation and finishing to the required outline shape by aprocess such as etching.

Whether the driver element is formed from a metal plate or metal film,its outline shape may instead of a circle be formed as a square,electrical connection with the internal conductors 21₄₁ and 21₄₂ ofcoaxial connection plugs 21₃₁ and 21₃₂ being effected in the cornerportions of the square.

Next will be explained the dimensions of driver element 21₆₁ for a casein which driver element 21₆₁ is driven in basic mode. When the outlineshape of driver element 21₆₁ is formed as a circle as shown in FIG. 6,if the specific inductive capacity of round insulation plate 21₅₁ isε_(r) and the design frequency is f_(o), the radius of driver element21₆₁ is preferably selected as substantially 1.841 C/(2π. f_(o).ε_(r)^(1/2)), and when the outline shape of driver element 21₆₁ is formed asa square, the length of one side of driver element 21₆₁ is preferablyselected as substantially C/(2f_(o). ε_(r) ^(1/2))(C being the speed oflight).

Next, in FIG. 7, 21₄₃ and 21₄₄ are the internal conductors of coaxialconnection plugs 21₃₃ and 21₃₄, respectively, 21₅₂ is a round insulationplate, and 21₆₂ is the second driver element; the material, method offabrication, and mutual electrical and mechanical relation of each ofthese parts being identical to the material, method of fabrication, andmutual electrical and mechanical relation of each of respective coaxialconnection plugs 21₃₁ and 21₃₂, internal conductors 21₄₁ and 21₄₂, roundinsulation plate 21₅₁, and first driver element 21₆₁ on the side ofsealed case 21₁.

FIG. 8 illustrates the operation of this phase shifting device. Theinput power E applied to the input terminal of 90° 3-dB hybrid circuit22 is distributed into two substantially equal portions and outputtedfrom output terminals 22₃ and 22₄, the phase of output E₁ of outputterminal 22₃ being delayed substantially 90° with respect to the phaseof output E₂ of output terminal 22₄.

Output is outputted to isolation terminal 22₂ according to thedifference between the impedance viewing the load side from outputterminal 22₃ and the impedance viewing the load side from outputterminal 22₄, and this output is absorbed by reflectionless terminator23; however, in a state in which output terminal 22₃ and the load arematched and output terminal 22₄ and the load are matched, the outputoutputted to isolation terminal 22₂ becomes extremely small, and as aresult, the permissible power of reflectionless terminator 23 may beextremely low.

Output E₁ of output terminal 22₃ of 90° 3-dB hybrid circuit 22 isapplied by way of coaxial cable 26₂ to the driver point at whichinternal conductor 21₄₂ of coaxial connection plug 21₃₂ of coupler 21connects to first driver element 21₆₁. The instantaneous value of theelectric field propagated from this driving point in the Z direction(the X-axis and Y-axis are determined as shown in FIG. 6, and thedirection perpendicular to the X- and Y-axis is the Z direction) isE_(x). Output E₂ of output terminal 22₄ of 90° 3-dB hybrid circuit 22 isapplied by way of coaxial cable 26₁ to the driver point at whichinternal conductor 21₄₁ of coaxial connection plug 21₃₁ of coupler 21 isconnected to first driver element 21₆₁, and the instantaneous value ofthe electric field propagated in the Z direction from this driver pointis E_(y). The instantaneous values E_(x) and E_(y) of the electric fieldare: ##EQU1##

The electric field propagated in the Z direction couples at the seconddriver element 21₆₂, which together with round insulation plate 21₅₂ andthe bottom wall of the second sealed case 21₂ forms the second driver;but if the angle formed between the straight line joining the center offirst driver element 21₆₁ with the driver point at which internalconductor 21₄₁ of coaxial connection plug 21₃₁ of coupler 21 connects tofirst driver element 21₆₁ and the straight line joining the center ofsecond driver element 21₆₂ with the driver point at which internalconductor 21₄₄ of coaxial connection plug 21₃₄ of coupler 21 connects tosecond driver element 21₆₂ is represented by φ, the output of coaxialconnection plug 21₃₄ is represented by E₃, and the output of coaxialconnection plug 21₃₃ is represented by E₄, the outputs E₃ and E₄ are:

    E.sub.3 =E.sub.y cosφ-E.sub.X sinφ

    E.sub.4 =E.sub.y sinφ-E.sub.X cosφ

The output E₃ of coaxial connection plug 21₃₄ is applied through inputterminal 24₃ to 90° 3-dB hybrid circuit 24, and output E₄ of coaxialconnection plug 21₃₃ is applied through input terminal 24₄ to 90° 3-dBhybrid circuit 24. If the output of isolation terminal 24₂ of 90° 3-dBhybrid circuit 24 is represented by E₅, and the output of outputterminal 24₁ is represented by E₆, outputs E₅ and E₆ are respectively:##EQU2##

In other words, in this phase shifting device, the phase of the outputof output terminal 24₁ of 90° 3-dB hybrid circuit 24 can be shifted by φwith respect to the phase of the input to input terminal 22₁ of 90° 3-dBhybrid circuit 22 by simply rotating the sealed cases 21₁ and 21₂ withrespect to each other by the angle φ.

FIG. 9 shows the reflection characteristics at coaxial connection plug21₃₁ (see FIG. 7 regarding the following dimensions) for a case in whichthe inside diameter of the cylinders having one closed end that formsealed cases 2l₁ and 21₂ of coupler 21 are selected as 0.285 λ_(o) whichis one of the size that give cutoff mode at the designed frequency,(λ_(o) being the free space wavelength corresponding to the designedfrequency f_(o)), the distance between the bottom wall of sealed case21₁ and the bottom wall of sealed case 21₂ is set at 0.089 λ_(o), thespecific inductive capacity of each of round insulation plates 21₅₁ and21₅₂ is set at 10, the dielectric dissipation factor of each of roundinsulation plates 21₅₁ and 21₅₂ is set at 0.0055, the thickness of roundinsulation plates 21₅₁ and 21₅₂ is set at 0.023 λ_(o), and each of thefirst and second driver elements 21₆₁ and 21₆₂ are formed in a circularshape of diameter 0.21 λ_(o). Here, the axis of abscissas shows therelative frequency with respect to the design frequency f_(o), and theaxis of ordinates shows the amount of return loss (dB).

FIG. 10 shows the transmission characteristics between coaxialconnection plugs 21₃₁ and 21₃₄ for a case in which each of thedimensions of coupler 21 is the same as for FIG. 9, the axis ofabscissas being equivalent to FIG. 9 and the axis of ordinates showingthe amount of transmission loss (dB).

As can be seen from FIG. 9 and FIG. 10, coupler 21 exhibits excellentreflection characteristics and transmission characteristics over a broadband.

Furthermore, the thickness of round insulation plates 21₅₁ and 21₅₂ ofcoupler 21 can be selected according to the transmission frequency band,and the bandwidth can be broadened by increasing the thickness from theselected thickness.

FIG. 11 shows observation results of changes in phase of the output fromoutput terminal 24₁ of 90° 3-dB hybrid circuit 24 with respect to thephase of the input to input terminal 22₁ of 90° 3-dB hybrid circuit 22,the axis of abscissas showing the frequencies relative to the designfrequency f_(o) and the axis of ordinates showing the amount of phaseshift (°) with respect to the angle of rotation φ, each of thedimensions of coupler 21 being selected in the same way as explained forFIG. 9, the phase shifting device being configured with 90° 3-dB hybridcircuit 22 connected to coupler 21 by way of coaxial cables 26₁ and 26₂and 90° 3-dB hybrid circuit 24 connected to coupler 21 by way of coaxialcables 27₁ and 27₂ as shown in FIG. 3, and φ representing the angle ofrotation by which the sealed cases 21₁ and 21₂ forming coupler 21 havebeen rotated relative to each other around their common cylindricalaxis.

As is clear from FIG. 11, regardless of the transmission frequency, theamount of phase shift always coincides with the angle of rotation φ ofsealed cases 21₁ and 21₂ making up coupler 21 with respect to each otheraround their common cylindrical axis.

FIG. 12 shows the observation results of the amount of transmission lossbetween input terminal 22₁ of 90° 3-dB hybrid circuit 22 and outputterminal 24₁ of 90° 3-dB hybrid circuit 24 under the same conditions asfor the observations in which the results of FIG. 11 were obtained, theaxis of abscissas being the same as for FIG. 11 and the axis ofordinates showing the amount of transmission loss (dB).

As is clear from FIG. 12, compared to the amount of transmission lossshown in FIG. 10 for coupler 21 alone, the addition of 90° 3-dB hybridcircuits 22 and 24, coaxial cables 26₁ and 26₂, as well as 27₁ and 27₂increases the transmission loss, but the degree of change in thefrequency characteristic of the amount of transmission loss is as forcoupler 21 alone.

The foregoing explanation relates to a case (see FIG. 7) in which sealedcases 21₁ and 21₂ of coupler 21 are formed from metal; the first driverinstalled within coupler 21 is formed from a microstrip antenna composedof sealed case 21₁, which is the ground conductor, round insulationplate 21₅₁, and driver element 21₆₁ ; and the second driver is formedfrom a microstrip antenna composed of sealed case 21₂, which is theground conductor, round insulation plate 21₅₂, and driver element 21₆₂.However, in a case in which sealed cases 21₁ and 21₂ are formed byapplying a metal film to the outer surface of a body composed of asuitable synthetic resin, the metal film applied to the outer surface ofthe body of sealed case 21₁ can serve as the ground conductor, the bodyof sealed case 21₁ can serve as round insulation plate 21₅₁, and thefirst driver composed of a microstrip antenna can therefore be formed byattaching driver element 21₆₁ to the inner surface of the bottom wall ofsealed case 21₁, and the second driver composed of a microstrip antennacan similarly be formed by attaching driver element 21₆₂ to the innersurface of the bottom wall of sealed case 21₂.

In a case in which sealed cases 21₁ and 21₂ are formed by multilayerstacking of dielectric plates, the first driver composed of a microstripantenna can be formed by attaching driver element 21₆₁ to the innersurface of the bottom wall of sealed case 21₁ and attaching a groundconductor to the outer surface of the bottom wall; and the second drivercomposed of a microstrip antenna can be formed by attaching driverelement 21₆₂ to the inner surface of the bottom wall of sealed case 21₂and attaching a ground conductor to the outer surface of the bottomwall.

Instead of forming the driver as a microstrip antenna, the driver canalso be formed from a slot antenna formed by providing a cross-shapedslot 21₇₁ in the central portion of metal plate or metal film 21₆₁forming the driver element as shown in FIG. 13, which is a sectionalview taken along the same line as FIG. 6. Other construction andreference numerals in FIG. 13 are as for FIG. 6.

In FIG. 14, which is a sectional view taken along the same line as FIG.7, 21₇₁ is cross-shaped slot, and 21₇₂, like 21₇₁, is a cross-shapedslot provided in the central portion of the metal plate or metal film21₆₂ forming the driver element, the other construction and referencenumerals being the same as for FIG. 7.

In this embodiment as well, if sealed cases 21₁ and 21₂ are formed byapplying a metal film to the outer surface of a base body composed of asuitable synthetic resin, the metal film applied to the outer surface ofthe base body can serve as the ground conductor and the base body itselfcan be used as round insulation plates 21₅₁ and 21₅₂ of FIG. 14; and ifsealed cases 21₁ and 21₂ are formed by multilayer stacking of dielectricplates, the first and second drivers composed of slot antennas can beformed by attaching driver elements 21₆₁ and 21₆₂ composed of metalfilms or metal plates provided with cross-shaped slots to the innersurface of each of the bottom walls of sealed cases 21₁ and 21₂, andproviding a ground conductor on the outer surface of each bottom wall.

Further, probes may be connected to internal conductors 21₄₁ and 21₄₂ ofcoaxial connection plugs 21₃₁ and 21₃₂ shown in FIG. 6 or FIG. 13, theseprobes being formed such that the longitudinal direction of both probesis parallel to metal plate or metal film 21₆₁, the portions of bothprobes extending in the longitudinal direction intersect at the centerpoint of metal plate or metal film 21₆₁, and this intersecting angle isa right angle. A driver composed of probes similar to the sealed case21₁ side may then be provided on the sealed case 21₂ side.

Whichever of the above constructions is adopted for the driversinstalled in each of sealed cases 21₁ and 21₂, the amount of phase shiftbetween the input and output is determined by the angle of relativerotation between sealed cases 21₁ and 21₂, and in order for sealed cases21₁ and 21₂ to rotate with respect to each other, any of the followingconstructions may be adopted: coaxial cables 26₁, 26₂, 27₁, and 27₂ areformed as flexible cables; the sealed case 21₂ side is fixed and sealedcase 21₁, coaxial cables 26₁ and 26₂, and 90° 3-dB hybrid circuit 22rotate as a unit; the sealed case 21₁ side is fixed and sealed case 21₂,coaxial cables 27₁ and 27₂, and 90° 3-dB hybrid circuit 24 rotate as aunit; or sealed case 21₁, coaxial cables 26₁ and 26₂, and 90° 3-dBhybrid circuit 22 are formed as one rotatable unit and sealed case 21₂,coaxial cables 27₁ and 27₂ and 90° 3-dB hybrid circuit 24 are formed asanother rotatable unit.

The foregoing explanations relate to cases in which sealed cases 21₁ and21₂ are each formed as a cylinder with one closed end, but either ofsealed case 21₁ or 21₂ may be formed as a cylindrical case with oneclosed end in which is installed either the first or second driver, andthe other side, i.e., sealed case 21₂ or 21₁ may be formed as adisk-shaped cover with the second or first driver attached to the innersurface, this cover being formed to rotatably fit with the end portionof the opening of the closed cylinder body.

As is clear from the foregoing explanation, in this phase shiftingdevice, the side of coaxial cables 26₁ and 26₂ and 90° 3-dB hybridcircuit 22 and the side of coaxial cables 27₁ and 27₂ and 90° 3-dBhybrid circuit 24 are formed symmetrically to each other across theplane cutting through the midsection of the coupler 21 at F--F in FIG.15; and consequently, precisely identical operation can be achieved asexplained in conjunction with FIG. 8 even if terminal 24₁ of 90° 3-dBhybrid circuit 24 is made the input terminal and terminal 22₁ of 90°3-dB hybrid circuit 22 is made the output terminal. The other referencenumerals of FIG. 15 are equivalent to those of FIG. 3.

The foregoing explanation relates to an example (see FIG. 8) in which90° 3-dB hybrid circuits 22 and 24 and reflectionless terminators 23 and25 have been used for the two-partition circuit of the input and thecombining circuit of the output, but for a case in which thetransmission frequency bandwidth is relatively narrow, the input-andoutput-side 90° 3-dB hybrid circuits 22 and 24 and reflectionlessterminators 23 and 25 can be replaced by two-branch terminal circuits,with one of coaxial cables 26₁ and 26₂ connecting coaxial connectionplugs 21₃₁ and 21₃₂ of coupler 21 with the two output terminals of thetwo-branch terminal circuit on the input side, for example, coaxialcable 26₂, being formed exactly one transmission quarter-wavelengthlonger than coaxial cable 26₁, and one of coaxial cables 27₁ and 27₂connecting coaxial connection plugs 21₃₃ and 21₃₄ of coupler 21 to thetwo input terminals of the two-branch terminal circuit on the outputside, for example coaxial cable 27₁, being formed exactly onetransmission quarter-wavelength longer than coaxial cable 27₂.

In this embodiment, although the lengths of coaxial cables 26₁ and 26₂must be made to differ by exactly one transmission quarter-wavelength,and the lengths of coaxial cables 27₁ and 27₂ similarly must be made todiffer by exactly one transmission quarter-wavelength, the difference inlengths for both sets of cables is fixed at one transmissionquarter-wavelength, and fabrication is therefore relatively easy.

If the difference in lengths between coaxial cables 26₁ and 26₂ and thedifference in lengths between coaxial cables 27₁ and 27₂ is selected tobe one quarter-wave-length of the center frequency of the transmissionband, the difference in length between the coaxial cables will notprecisely match the quarter-wavelength for frequencies outside thecenter frequency, but since this embodiment is intended for applicationsin which the transmission frequency band is relatively narrow, anyoperational error arising due to variance from the quarter-wavelength isminute and presents no practical problem.

The foregoing explanation relates to a case in which the phase shiftingdevice of the present invention is constructed by assemblingthree-dimensional constituent elements, but the entire structure can beminiaturized by forming 90° 3-dB hybrid circuits 22 and 24 andreflectionless terminators 23 and 25 on a printed circuit board using aprinted wiring method, and forming coaxial cables 26₁, 26₂, 27₁ and 27₂as microstrip wiring.

The entire structure may also be made extremely compact and concise byproviding dielectric layers on the outer surfaces of sealed cases 21₁and 21₂ of coupler 21, and then forming by a printed wiring method onthe dielectric layer provided on the outer surface of sealed case 21₁microstrip wiring that takes the place of 90° 3-dB hybrid circuit 22,reflectionless terminator 23 and coaxial cables 26₁ and 26₂, and formingby a printed wiring method on the dielectric layer provided on the outersurface of sealed case 21₂ microstrip wiring that takes the place of 90°3-dB hybrid circuit 24, reflectionless terminator 25 and coaxial cables27₁ and 27₂.

In a case in which two-branch terminal circuits are used in place of 90°3-dB hybrid circuits 22 and 24 and reflectionless terminators 23 and 25,the entire structure can be miniaturized through formation on printedcircuit boards or on dielectric layers provided on the outer surfaces ofeach of sealed cases 21₁ and 21₂.

FIG. 16 presents a phase shifting device according to another embodimentof the present invention.

The phase shifting device of this embodiment is constructed from acoupler 31 composed of cylindrical sealed cases 31₁ and 31₂ having oneclosed end, and terminals 31₃₁ -31₃₃ composed of, for example, coaxialconnection plugs; 90° 3-dB hybrid circuit 32 composed of, for example, aquarter-wave coupled line-type directional coupler including inputterminal 32₁, isolation terminal 32₂, and output terminals 32₃ and 32₄ ;coaxial cable 33₁ connecting terminal 31₃₃ and input terminal 32₁ ; andcoaxial cable 33₂ connecting terminal 31₃₂ and isolation terminal 32₂.Here, considering a signal inputted to input terminal 32₁, the phase ofthe output from output terminal 32₃ is delayed substantially 90° withrespect to the phase of the output of output terminal 32₄. In addition,the length of each of coaxial cable 33₁ and 33₂ is adjusted such thatthe phase difference between inputs at the input end of each of coaxialcables 33₁ and 33₂ is maintained unchanged when outputted from theoutput end of each of coaxial cables 33₁ and 33₂.

FIG. 17 shows a side view of coupler 31 of FIG. 16, and FIG. 18 shows aplan view of the sealed case 31₁ side of coupler 31 as seen from theside of the bottom wall, the reference numerals used in FIGS. 17 and 18being the same as those used in FIG. 16. FIG. 19 is an enlargedsectional view taken at line G--G of FIG. 16, FIG. 20 is an enlargedsectional view taken at line H--H of FIG. 17, and FIG. 21 is an enlargedsectional view taken at line I--I of FIG. 18.

As can be clearly seen from FIG. 21, stepped portions are formed in theside walls at the end portions of the openings of each of sealed cases31₁ and 31₂, the end portion of the opening of one of the sealed cases,in this case sealed case 31₂, fitting inside the end portion of theopening of the other sealed case 31₁, the two sealed cases 31₁ and 31₂being mechanically and electrically coupled, and sealed cases 31₁ and31₂ able to rotate relative to each other around their cylindrical axis.

Sealed cases 31₁ and 31₂ are manufactured by machining a metal block orpress-forming a metal sheet in the prescribed shape; by forming asuitable synthetic resin in a preliminary form of the prescribed shapeand subsequently applying a metal film to the surface by an electrolessplating or vacuum evaporation process; or by multilayer stacking ofdielectric plates having an appropriate dielectric constant and formingas a cylinder with one closed end that shields electromagnetic energy inaccordance with Snell's law.

Coaxial connection plugs 31₃₁ to 31₃₃ have internal conductors 31₄₁ to31₄₃. Round insulation plates 31₅₁ and 31₅₂ are composed of a materialhaving excellent high-frequency characteristics such as an organicmaterial such as polyethylene or fluorinated ethylene or an inorganicmaterial such as a ceramic and have a thickness less than thetransmission wavelength, round insulation plate 31₅₁ being secured tothe inner surface of the bottom wall of sealed case 31₁, roundinsulation plate 31₅₂ being secured to the inner surface of the bottomwall of sealed case 31₂, and each being secured using a suitableadhesive.

Metal plate 31₆₁ is secured to the surface of round insulation plate31₅₁ using a suitable adhesive, and in addition, a portion of itsperiphery is electrically connected to internal conductor 31₄₁ ofcoaxial connection plug 31₃₁. First driver composed of a microstripantenna is formed with sealed case 31₁ on the opposing side ofinsulation plate 31₅₁ serving as ground conductor, metal plate 31₆₁serving as first driver element, and the connection point betweeninternal conductor 31₄₁ of coaxial connection plug 31₃₁ and metal plate31₆₁ serving as the driver point.

Metal plate 31₆₂ is secured to the surface of round insulation plate31₅₂ using a suitable adhesive, and in addition, portions of itsperiphery are electrically connected to internal conductors 31₄₂ and31₄₃ of coaxial connection plugs 31₃₂ and 31₃₃. Second driver composedof a microstrip antenna is formed with sealed case 31₂ on the opposingside of insulation plate 31₅₂ serving as ground conductor, metal plate31₆₂ serving as second driver element, and the connection points betweenmetal plate 31₆₂ and internal conductors 31₄₂ and 31₄₃ of coaxialconnection plugs 31₃₂ and 31₃₃ serving as the driver points.

As can be seen from FIG. 20, a right angle is formed by the intersectionof the straight line joining the center of metal plate 31₆₂ with thedriving point composed of the connection point between internalconductor 31₄₂ of coaxial connection plug 31₃₂ and metal plate 31₆₂, andthe straight line joining the center of metal plate 31₆₂ with thedriving point formed by the connection point between internal conductor31₄₃ of coaxial connection plug 31₃₃ and metal plate 31₆₂.

In addition, the spacing between first driver element 31₆₁ and seconddriver 31₆₂ is set at less than the transmission wavelength.

The external conductor of coaxial connection plug 31₃₁ is electricallyconnected to sealed case 31₁, and the external conductors of each ofcoaxial connection plugs 31₃₂ and 31₃₃ are connected to sealed case 31₂; but, as shown in FIG. 21, a gap is provided by removing a portion ofthe sealed case 31₁ in the vicinity of internal conductor 31₄₁ and a gapis provided by removing a portion of sealed case 31₂ in the vicinity ofinternal conductor 31₄₃ such that internal conductors 31₄₁ and 31₄₃ ofcoaxial connection plugs 31₃₁ and 31₃₃ do not mechanically contactsealed cases 31₁ and 31₂. Although not shown in FIG. 21, a gap issimilarly provided in sealed case 31₂ in the vicinity of internalconductor 31₄₂ of coaxial connection plug 31₂₁.

Rather than using an adhesive as a means of securing metal plate 31₆₁ or31₆₂ to the surface of round insulation plate 31₅₁ or 31₅₂, the centerof metal plate 31₆₁ or 31₆₂ (the portion where electric field intensityis 0) may be secured to round insulation plate 31₅₁ or 31₅₂ using asetscrew, or alternatively the center of metal plate 31₆₁ or 31₆₂ may bescrewed to the bottom wall of sealed case 31₁ or 31₂ through roundinsulation plate 31₅₁ or 31₅₂.

Rather than forming the driver element of the microstrip antennaconstituting the first or second driver from metal plate 31₆₁ or 31₆₂,the driver element may be formed by applying a metal film to the surfaceof round insulation plate 31₅₁ or 31₅₂ using a vacuum evaporationprocess and finishing to the required outline shape by a process such asetching.

Whether the driver element is formed from a metal plate or metal film,its outline shape may be formed as a square instead of the circle shownin FIG. 19 and FIG. 20.

Regarding the dimensions of driver elements 31₆₁ and 31₆₂ for cases inwhich driver elements 31₆₁ and 31₆₂ are driven in basic mode, if theoutline shape of these elements is formed as a circle, the specificinductive capacity of round insulation plates 31₅₁ and 31₅₂ is ε_(r) andthe design frequency is f_(o), the radius of driver elements 31₆₁ and31₆₂ is preferably selected to be substantially 1.841 C/(2π. f_(o).ε_(r) ^(1/2)); and if the outline shape of driver elements 31₆₁ and 31₆₂is formed as a square, the length of one side is preferably selected tobe substantially C/(2f_(o). ε_(r) ^(1/2)) (where C is the speed oflight).

FIG. 22 illustrates the operation of the present phase shifting device.

As FIG. 21 illustrates, the input applied to coaxial connection plug31₃₁ of coupler 31 passes through internal conductor 31₄₁ and drivesdriver element 31₆₁ in the first driver.

If the X-axis and Y-axis are established as shown in FIG. 19, FIG. 20,and FIG. 22A, electric field vector E produced by driver element 31₆₁driven as described above can be divided between two orthogonalcomponents E_(X) and E_(Y) as shown in FIG. 22A. These couple at driverelement 31₆₂ of the second driver in the form:

    E=E.sub.X +E.sub.Y =E cosφ+sin φ

As described hereinabove, this device is formed such that a right angleis formed by the intersection of the straight line joining the center ofdriver element 31₆₂ with the driving point constituted by the connectionpoint between driver element 31₆₂ and internal conductor 31₄₂ of coaxialconnection plug 31₃₂ and the straight line joining the center of driverelement 31₆₂ with the driving point constituted by the connection pointbetween driver element 31₆₂ and internal element 31₄₃ of coaxialconnection plug 31₃₃ ; and therefore, when driver element 31₆₂ is drivenin basic mode, coupling between coaxial connection plugs 31₃₂ and 31₃₃becomes sparse and quadrature mode coupling is enabled.

The quadrature mode coupling to driver element 31₆₂ causes componentE_(X) to be outputted from coaxial connection plug 31₃₂ and componentE_(Y) to be outputted from coaxial connection plug 31₃₃ , the twooutputs being respectively inputted to terminals 32₁ and 32₂ of 90° 3-dBhybrid circuit 32 by way of coaxial cables 33₁ and 33₂.

If the output of output terminals 32₄ and 32₃ of 90° 3-dB hybrid circuit32 are E₁ and E₂, respectively: ##EQU3##

Although the phase of output E₁ shifts in a counterclockwise directionwith increase in declination angle φ of electric field vector E from theX-axis as shown in FIG. 22A, the amplitude remains unchanged. The phaseof output E₂ also shifts in a clockwise direction with increase indeclination angle φ of electric field vector E from the X-axis, butagain, the amplitude remains unchanged. Accordingly, if the declinationangle φ of electric field vector E from the X-axis is 45° or 225°, theamplitude as well as the phase of both outputs E₁ and E₂ are equal, butif the declination angle φ increases from 45° or 225°, the phase ofoutput E₁ shifts in the advance direction, and the phase of output E₂shifts in the delay direction. If the declination angle φ of electricfield vector E from the X-axis further increases to 135° or 315°, thephase relation between outputs E₁ and E₂ is mutually reversed.

FIG. 23 shows the reflection characteristic at coaxial connection plug31₃₁ observed after removing coaxial cables 33₁ and 33₂ from coaxialconnection plugs 31₃₂ and 31₃₃ , (see FIG. 21 regarding the followingdimensions) the inner diameter of the cylinders with one closed endforming sealed cases 31₁ and 31₂ of coupler 31 being selected as 0.285λ_(o) (λ_(o) being the free-space wavelength corresponding to the designfrequency f_(o)), the distance of opposition between the bottom wall ofsealed case 31₁ and the bottom wall of sealed case 31₂ as 0.089 λ_(o),the specific inductive capacity of round insulation plates 31₅₁ and 31₅₂as 10, the dielectric dissipation factor of each of round insulationplates 31₅₁ and 31₅₂ as 0.0055, the thickness of each of roundinsulation plates 31₅₁ and 31₅₂ as 0.023 λ_(o), the outline shape offirst and second driver elements 31₆₁ and 31₆₂ being formed as a circlewith a diameter of 0.21 λ_(o), the axis of abscissas in the figure beingthe relative frequency for the design frequency f_(o), and the axis ofordinates being the amount of return loss (dB). FIG. 24 shows thetransmission characteristics between coaxial connection plugs 31₃₁ and31₃₃ observed with coaxial cable 31₁ and 33₂ removed from coaxialconnection plugs 31₃₂ and 31₃₃ and the selected values of the dimensionsof each of the parts of coupler 31 being the same as described for FIG.23, the horizontal axis of the figure being the same as for FIG. 23 andthe vertical axis being the amount of transmission loss (dB).

As is clear from FIG. 23 and FIG. 24, coupler 31 exhibits excellentreflection characteristics and transmission characteristics across abroad band.

In addition, the thickness of round insulation plates 31₅₁ and 31₅₂ incoupler 31 can be selected according to the transmission frequency band,and the bandwidth can be broadened by increasing the selected thickness.

FIG. 25 shows the results of observing the phase shift of output E₁ ofcoaxial connection plug 31₃₃ and output E₂ of coaxial connection plug31₃₂ upon change of declination angle φ to 90° or 135° with 45° as astandard. Here, the same values are selected for the dimensions of eachpart of coupler 31 as described for FIG. 23; the phase shifting deviceis configured as shown in FIG. 16, wherein 90° 3-dB hybrid circuit 32 isconnected to coupler 31 by way of coaxial cables 33₁ and 33₂ ; andsealed cases 31₁ and 31₂ , which make up coupler 31, are rotatedrelative to each other around their common cylindrical axis. The angleof declination φ is formed by the straight line joining the center ofdriver element 31₆₂ with the connection point between internal conductor31₄₂ of coaxial connection plug 31₃₂ and driver element 31₆₂ in thesecond driver installed on the sealed case 31₂ side, i.e., the X-axis,and the electric field vector E arising due to drive of driver element31₆₁ in the first driver installed on the sealed case 31₁ side. For bothoutputs E₁ and E₂, the absolute value of the change in phase and thechange in declination angle φ match without any dependence ontransmission frequency, and the signs of phases of outputs E₁ and E₂differ. Accordingly, the phase difference between outputs E₁ and E₂ withrespect to change in declination angle φ is 2 φ.

The axis of abscissas of FIG. 25 is the same as for FIG. 23, and theaxis of ordinates shows declination angle φ, i.e., the amount of phaseshift (°) with respect to the relative angle of rotation φ betweensealed cases 31₁ and 31₂ .

FIG. 26 shows the amount of transmission loss between coaxial connectionplug 31₃₁ of coupler 31 and output terminal 32₃ of 90° 3-dB hybridcircuit 32, and between coaxial connection plug 31₃₁ of coupler 31 andoutput terminal 32₄ of 90° 3-dB hybrid circuit 32, the observationresults being obtained under the same conditions as those for FIG. 25,the axis of abscissas being the same as FIG. 25 and the axis ofordinates showing the amount of transmission loss (dB).

As is clear from FIG. 26, although the addition of 90° 3-dB hybridcircuit 32 and coaxial cables 33₁ and 33₂ results in increasedtransmission loss as compared with the amount of transmission loss forthe case shown in FIG. 24 in which coupler 31 alone is used, thedifferences in the change of phase shift of outputs E₁ and E₂ withrespect to the change in angle φ or in amplitude of outputs E₁ and E₂are virtually negligible.

FIG. 27 shows an example which employs both outputs E₂ and E₁ of outputterminals 32₃ and 32₄ of 90° 3-dB hybrid circuit 32. Reference numeral34 indicates the phase shifting device shown in FIG. 16, 31₃₁ is theinput terminal of coupler 31 in phase shifting device 34, 32₃ and 32₄are the output terminals of 90° 3-dB hybrid circuit 32 in phase shiftingdevice 34, and 35₁ and 35₂ are both subarray antennas composed of aplurality of element antennas.

The locus joining the peaks of each of output vectors E_(X) and E_(Y)corresponding to the change in the relative angle of rotation φ betweensealed cases 31₁ and 31₂ which make up coupler 31 in phase shiftingdevice 34 is an oval, but the angle at which output vectors E_(X) andE_(Y) begin to describe an oval both differs by 90° and is in theopposite direction of rotation, and consequently, the phase differencebetween outputs E₂ and E₁ can be freely selected. Accordingly, thedirection of maximum radiation and the side-lobe characteristics of thearray antenna composed of subarray antennas 35₁ and 35₂ can becontrolled by supplying outputs E₂ and E₁ of output terminals 32₃ and32₄ as the driving power of subarray antennas 35₁ and 35₂.

A comparison of FIG. 27 and FIG. 2 clearly shows that, while thestructure of a power supply circuit using a phase shifting device of theprior art was complicated by the requirement for a transmission pathhaving a standard amount of phase shift and a two-branch circuit foreach phase shifter, the use of a phase shifting device of the presentinvention results in a power supply circuit of extremely simpleconstruction because the phase shifting device of the present inventionhas an effect equivalent to the combination of a prior-art phaseshifting device, a transmission path having a standard amount of phaseshift, and a two-branch circuit.

The foregoing description relates to an example (see FIG. 21) in whichsealed cases 31₁ and 31₂ of coupler 31 are formed from metal; the firstdriver installed in coupler 31 is formed from a microstrip antennacomposed of sealed case 31₁ which serves as a ground conductor, roundinsulation plate 31₅₁ , and driver element 31₆₁ ; and the second driveris formed from a microstrip antenna composed of sealed case 31₂ whichserves as a ground conductor, round insulation plate 31₅₂ , and driverelement 31₆₂ . However, if sealed cases 31₁ and 31₂ are each formed byapplying a metal film to the outer surface of a base body composed of asuitable synthetic resin, the metal film applied to the outer surface ofthe base body of sealed case 31₁ can be used as a ground conductor, thebase body itself of sealed case 31₁ can be used as round insulationplate 31₅₁ , and as a result, the first driver composed of a microstripantenna can be formed by attaching driver element 31₆₁ to the innersurface of the bottom wall of sealed case 31₁ , and the second drivercomposed of a microstrip antenna can be formed by attaching driverelement 31₆₂ to the inner surface of the bottom wall of sealed case 31₂.

For a case in which sealed cases 31₁ and 31₂ are formed by multilayerstacking of dielectric plates, the first driver composed of a microstripantenna can be formed by attaching driver element 31₆₁ to the innersurface and attaching a ground conductor to the outer surface of thebottom wall of sealed case 31₁ , and the second driver composed of amicrostrip antenna can be formed by attaching driver element 31₆₂ to theinner surface and attaching a ground conductor to the outer surface ofthe bottom wall of sealed case 31₂ .

As shown in FIG. 28 in a sectional view similar to that of FIG. 20,instead of being formed from a microstrip antenna, the second driver maybe formed from a slot antenna achieved by providing a cross-shaped slot31₇ in the center of metal plate or metal film 31₆₂ forming the driverelement; and the first driver may be formed as a slot antenna composedof only a slot in the vertical direction or in the horizontal directionof the cross-shaped slot of FIG. 28. Other reference numerals andconstruction in FIG. 28 is as for FIG. 20.

In this embodiment as well, if sealed cases 31₁ and 31₂ are formed byapplying a metal film to the outer surface of a base body composed of asuitable synthetic resin, the metal film applied to the outer surface ofthe base body may be used as the ground conductor, and the base bodyitself can be used as round insulation plates 31₅₁ and 31₅₂ ; and ifsealed cases 31₁ and 31₂ are formed by multilayer stacking of dielectricplates, first and second drivers composed of slot antennas can be formedby attaching driver elements 31₆₁ and 31₆₂ composed of a metal plate ormetal film provided with a single-line slot or a cross-shaped slot tothe inner surfaces of the bottom walls of each of sealed cases 31₁ and31₂ and attaching ground conductors to the outer surfaces of each bottomwall.

In addition, the first driver may be formed by connecting a probe tointernal conductor 31₄₁ of coaxial conection plug 31₃₁ shown in FIG. 19;and the second driver may be formed by connecting probes to internalconductors 31₄₂ and 31₄₃ of coaxial connection plug 31₃₂ and 31₃₃ shownin FIG. 20, the longitudinal direction of both probes being parallel tometal plate or metal film 31₆₂ and the portions extending in thelongitudinal direction of both probes intersecting at the center pointof metal plate or metal film 31₆₂, this intersection being a rightangle.

In either of the above-described constructions of the first and seconddrivers installed in sealed cases 31₁ and 31₂, respectively, the amountof phase shift between input and output is determined according to therelative angle of rotation between sealed cases 31₁ and 31₂, and torotate sealed cases 31₁ and 31₂ relative to each other, a constructionmay be adopted wherein sealed case 31₂, coaxial cables 33₁ and 33₂, and90° 3-dB hybrid circuit 32 are fixed and sealed case 31₁ is caused torotate; wherein sealed case 31₁ is fixed and sealed case 31₂, coaxialcables 33₁ and 33₂, and 90° 3-dB hybrid circuit 32 are caused to rotateas a unit; or wherein sealed case 31₁ and 90° 3-dB hybrid circuit 32 arefixed, coaxial cables 33₁ and 33₂ is formed from a flexible cable, andsealed case 31₂ is caused to rotate.

The foregoing explanation relates to a case in which sealed cases 31₁and 31₂ are both formed as cylinders with one closed end, but eithersealed case 31₁ or 31₂ may be formed as a cylinder with one closed endin which the first or second driver is installed, and the other sealedcase, i.e., sealed case 31₂ or 31₁ may be formed as a disk-shaped coverwith the second or first driver attached to its inner surface and formedsuch that the cover rotatably fits with the end portion of the openingof the cylinder with one closed end.

The foregoing explanation relates to a case in which 90° 3-dB hybridcircuit 32 is formed as a quarter-wave coupled-line directional coupler,but the hybrid circuit may also be formed as a branch line directionalcoupler.

In addition, for cases in which the transmission frequency bandwidth isrelatively narrow, a two-branch terminal circuit may take the place of90° 3-dB hybrid circuit 32, and the length of one of coaxial cables 33₁and 33₂, for example coaxial cable 332 , may be formed exactly onetransmission quarter-wavelength longer than coaxial cable 33₁.

In this embodiment, the lengths of coaxial cable 33₁ and 33₂ must differby exactly one transmission quarter-wavelength, but fabrication isrelatively easy because the difference in length between coaxial cables33₁ and 33₂ is fixed at one transmission quarter-wavelength.

If the difference in lengths between coaxial cables 33₁ and 33₂ isselected to be one transmission quarter-wavelength for the centerfrequency of the transmission band, the difference in length between thecoaxial cables will not precisely match the quarter-wavelength forfrequencies outside the center frequency, but since this embodiment isintended for applications in which the transmission frequency band isrelatively narrow, any operational error arising due to variance fromthe quarter-wavelength is minute and presents no practical problem.

The foregoing explanation relates to a case in which the phase shiftingdevice is constructed by assembling three-dimensional constituentelements, but the entire structure can be miniaturized by forming 90°3-dB hybrid circuit 32 on a printed circuit board using a printed wiringmethod and forming coaxial cables 33₁ and 33₂ as microstrip wiring.

The entire structure may also be made extremely compact and concise byproviding a dielectric layer on the outer surface of sealed case 31₂ ofcoupler 31, and then employing a printed wiring method to form 90° 3-dBhybrid circuit 32 and microstrip wiring that takes the place of coaxialcables 33₁ and 33₂.

In a case in which a two-branch terminal circuit takes the place of 90°3-dB hybrid circuit 32, the entire structure can be miniaturized byforming this component on a printed circuit board or on a dielectriclayer provided on the outer surface of sealed cases 31₂.

What is claimed is:
 1. A phase shifting device comprising:two-partitioncircuit means for partitioning input power into two substantially equalportions having a mutual phase difference of substantially 90°; firstdriver means for generating a circularly polarized wave that is drivenby two-partitioned output of said two-partition circuit means; seconddriver means for receiving said circularly polarized wave generated bysaid first driver means; a sealed case comprising first and secondcylinders each having one cylindrical side wall and one closed end onwhich one of said first and second driver means is installed; an endportion of said side wall of said first cylinder fitting with an endportion of said side wall of said second cylinder; said first and secondcylinders being rotatable relative to each other around theircylindrical axis; inner diameters of said first and second cylindersgiving cutoff modes at the frequency of the wave driven by said firstdriver means; and combining circuit means for combining linearlypolarized orthogonal components generated from said circularly polarizedwave received by said second driver means.
 2. A phase shifting devicecomprising:two-partition circuit means for partitioning input power intotwo substantially equal portions having a mutual phase difference ofsubstantially 90°; first driver means for generating a circularlypolarized wave that is driven by two-partitioned output of saidtwo-partition circuit means; second driver means for receiving saidcircularly polarized wave generated by said first driver means; a sealedcase comprising a cylinder with one cylindrical side wall and one closedend on which either one of said first and second driver means isinstalled, and a disk-shaped cover having one circular end which fitswith an end portion of said side wall of said cylinder and upon theinner surface of which is attached the other of said first and seconddriver means, said cylinder and said cover being rotatable relative toeach other around a cylindrical axis of said cylinder, an inner diameterof said cylinder giving cutoff modes at the frequency of the wave drivenby said first driver means; and combining circuit means for combininglinearly polarized orthogonal components generated from said circularlypolarized wave received by said second driver means.
 3. A phase shiftingdevice comprising:an input terminal; first driver means for generating alinearly polarized wave that is driven by an input applied to said inputterminal; second driver means for receiving said orthogonal componentsof said linearly polarized wave generated by said first driver means; asealed case comprising first and second cylinders each having onecylindrical side wall and one closed end on which one of said first andsecond driver means is installed; an end portion of said side wall ofsaid first cylinder fitting with an end portion of said side wall ofsaid second cylinder; said first and second cylinders being rotatablerelative to each other around their cylindrical axis; inner diameters ofsaid first and second cylinders giving cutoff modes at the frequency ofthe wave driven by said first driver means; and combining circuit meansfor combining two outputs generated from two orthogonal components ofsaid linearly polarized wave received by said second driver means.
 4. Aphase shifting device comprising:an input terminal; first driver meansfor generating a linearly polarized wave that is driven by an inputapplied to said input terminal; second driver means for receiving saidorthogonal components of said linearly polarized wave generated by saidfirst driver means; a sealed case comprising a cylinder with onecylindrical side wall and one closed end on which either one of saidfirst and second driver means is installed, and a disk-shaped coverhaving one circular end which fits with an end portion of said side wallof said cylinder and upon the inner surface of which is attached theother of said first and second driver means, said cylinder and saidcover being rotatable relative to each other around a cylindrical axisof said cylinder, an inner diameter of said cylinder giving cutoff modesat the frequency of the wave driven by said first driver means; andcombining circuit means for combining two outputs generated from twoorthogonal components linearly polarized wave received by said seconddriver means.
 5. A phase shifting device according to any one of claims1-4, wherein said first and second driver means each comprise microstripantennas.
 6. A phase shifting device according to any one of claims 1-4,wherein said first and second driver means each comprise slot antennas.7. A phase shifting device according to any one of claims 1-4, whereinsaid combining circuit means comprises a 90° 3-dB hybrid circuit.
 8. Aphase shifting device according to any one of claims 1-4, wherein saidcombining circuit means comprises a two-branch terminal circuit.